RICHMOND -- The beverage industry isn't the only corporate entity spending big bucks to influence an election here.

Moving Forward, which has heavy backing from Chevron Corp., has spent nearly $1.2 million to support three City Council candidates and oppose two others, according to campaign finance reports filed Thursday. Meanwhile, The Community Coalition Against Beverage Taxes has spent nearly $2.5 million to defeat the city's proposed tax on sugar-sweetened beverages.

Add in money raised by nine council candidates, police and fire unions, a pro-sugar-sweetened beverage tax group and the Black American Policical Action Committee, and total political spending in the city is approaching $4 million ahead of the Nov. 6 election.

City Clerk Diane Holmes could not confirm whether this is the most expensive campaign in the city's long and colorful political history, but no one can recall an election season that has drawn this much spending.

Moving Forward and The Community Coalition Against Beverage Taxes have more in common than their backing from multibillion-dollar corporate interests. Both independent campaign committees have paid hundreds of thousands of dollars to Barnes, Mosher, Whitehurst, Lauter and Partners, a San Francisco-based public relations and consulting firm, and both enjoy broad overlap in campaign platforms.

Moving Forward, described as a "coalition of labor unions, small businesses and public safety and firefighters associations ... major funding by Chevron," is supporting three candidates who oppose Measure N, the penny-per-ounce tax on sales of sugar-sweetened beverages, and opposing two others who support the measure.

Billboards for Chevron-backed candidates Bea Roberson, Nat Bates and Gary Bell bear an obvious resemblance to the "No on N" campaign signs that saturate nearly every block of the city. Roberson, Bates and Bell all oppose Measure N.

Backers of Measure N, including council candidates Marilyn Langlois and Eduardo Martinez, have been outspent by more than 50 to 1 while trying to push their message that the tax can help curb childhood obesity and fund youth recreation programs.

But spokesmen for corporate-backed campaign committees say there is no connection.

"Moving Forward is totally independent and geared toward providing all the information to voters so they know about the candidates running for office," said committee spokeswoman Alex Doniach.

Chuck Finnie, vice president of media and communications for Barnes, Mosher, Whitehurst, Lauter and Partners, said his firm has been hired by both campaigns but that each has "independent objectives."

"There is no partnership between the Measure N committee and Moving Forward," Finnie said, adding that there are "stylistic similarities" in mailers, billboards and signs because his firm designs those materials for both clients.

Finnie also noted that his firm is leading the No on N campaign but playing a smaller role in organizing advertising efforts for Moving Forward, the Chevron-backed group.

Many observers see the massive campaign spending -- and the presence of Barnes, Mosher, Whitehurst, Lauter and Partners -- as a continuation of the political slugfest waged here in 2010. In that election, Chevron spent nearly $1 million trying to oust Green Party Mayor Gayle McLaughlin and retain two council incumbents. The Chevron-backed incumbents were swept from office, and McLaughlin retained her seat.

McLaughlin and her progressive allies got a boost that year from Measure U, an advisory measure in which residents roundly rejected a proposed casino at Point Molate. The Chevron-backed incumbents who lost were pro-casino, while the winners were anti-casino.

The winning campaign rejecting the casino was run by Barnes, Mosher, Whitehurst, Lauter and Partners, the firm now working for the beverage giants and Chevron.

Contact Robert Rogers at 510-262-2726 or rrogers@bayareanewsgroup.com and follow Twitter.com/roberthrogers.